With dentists’ fees rising far faster than inflation and more than 100 million people lacking dental insurance, the percentage of Americans with untreated cavities began rising this decade, reversing a half-century trend of improvement in dental health, according to an article in The New York Times.

Figures from the Centers for Disease Control and Prevention show that in 2003 and 2004, the most recent years with data available, 27 percent of children and 29 percent of adults had untreated cavities. The level of untreated decay was the highest since the late 1980s and significantly higher than that found in a survey from 1999 to 2002.

Many poor and lower-middle-class families do not receive adequate care, in part because most dentists want customers who can pay cash or have private insurance, and they do not accept Medicaid patients. As a result, publicly supported dental clinics have months-long waiting lists. At the pediatric clinic managed by the state-supported University of Florida dental school, for example, low-income children must wait six months for surgery.

In some cases, the results of poor dental care have been deadly. A child in Mississippi and another in Maryland died this year from infections caused by decayed teeth. The issue from a public health standpoint, some say, is that even as so many patients go untreated, business is booming for most dentists. They are making more money while working shorter hours, on average, even as the nation’s number of dentists, per person, has declined.

The lack of dental care is not restricted to the poor and their children, the data shows. Experts on oral health say about 100 million Americans—including many adults who work and have incomes well above the poverty line—are without access to care.

A federal survey shows that 27 percent of adults without insurance saw a dentist in 2004, down from 29 percent in 1996, when dental fees were significantly lower, even after adjusting for inflation. For adults with private insurance, the rate was virtually unchanged, at 57 percent, up from 56 percent. Since 1990, the number of dentists in the United States has been roughly flat, about 150,000 to 160,000, while the population has risen about 22 percent. In addition, more dentists are working part time. Partly as a result, dental fees have risen much faster than inflation. In real dollars, the cost of the average dental procedure rose 25 percent from 1996 to 2004. The average American adult patient now spends roughly $600 annually on dental care, with insurance picking up about half the tab.